Improper Link Resolution Before File Access ('Link Following')
The to-upgrade plugin in feta 1.4.16 allows local users to overwrite arbitrary files via a symlink on the (1) /tmp/feta.install.$USER and (2) /tmp/feta.avail.$USER temporary files.
CWE-59 - Improper Link Resolution Before File Access
'Improper link resolution before file access' occurs when software accesses a file resource but fails to verify that the file isn't a link or shortcut to another file. An attacker can potentially gain access to arbitrary files and from there the impact can vary, depending on the application, from sensitive data exposure to remote code execution.